1. Technical Field
The inventive concept relates to a high density variable resistive memory and a method of manufacturing the same, and more particularly, to a high density phase-change random access memory (PCRAM) device and a method of manufacturing the same.
2. Related Art
PCRAMs, a kind of variable resistive memory device, include a phase-change material of which a resistance is changed depending on a temperature. The phase-change material includes a chalcogenide material such as germanium (Ge), antimony (Sb), and tellurium (Te). The phase-change material is changed between an amorphous state and a crystalline state, depending on the temperature to define reset (or logic “1”) and set (or logic “0”).
In PCRAMs like dynamic random access memories (DRAMS), each memory cell defined by a word line and a bit line may include a variable resistor formed of a phase-change material and a switching element configured to selectively drive the variable resistor.
As shown in FIG. 1, memory cells are arranged at intersections of word lines WL1 and WL2 and bit lines BL1 and BL2. Each of the memory cells is designed to have a minimum 4F2 area by considering a word line pitch and a bit line pitch. The term ‘F’ means a critical dimension.
However, with demands on high integration, a PCRAM may be required to decrease the area of each cell.